This invention relates to liquid/solid separation equipment used in the industrial, municipal, waste, tailings, chemical, and minerals processing technologies, and more particularly to mechanical drive means for sedimentation tanks used for thickening and clarifying slurry, and methods thereof.
Slurry 1008 entering a sedimentation tank 1000 typically comprises particles (solid sediments) which are suspended within a liquid fraction. The sedimentation tank 1000 serves to thicken or clarify the slurry 1008. In some instances, the sedimentation tank 1000 may agglomerate the suspended particles using flocculent, thereby allowing the sediments to settle to the bottom 1006 of the tank and form sludge. The sludge is driven to a central lower outlet 1010 in the tank using a rotating rake assembly 1002. Typically, a centrally-located drive having one or more motors turns the rake assembly 1002. The drive may be mounted to a center pillar 1012, or may otherwise be mounted to a bridge 1004 spanning a radius or entire diameter of the sedimentation tank 1000.
Conventional drive designs are limited in the amount of torque that they can handle. Accordingly, if too much sludge builds up at the bottom 1006 of a sedimentation tank 1000, resistance to the rake assembly 1002 increases, and can place large bending stresses on the main ring gear 60 of the drive 1.